Currently, a projector generally projects, in a fixed size, an image onto a plane during operation process. When part of a region of the projection plane covered by a projected image is uneven, for example, a wall size may be smaller than the size of the projected image, the size of the projected image generally needs to be adjusted by adjusting a focal length of a lens in the projector manually in order to exclude the uneven part from the projected image. Thus, the region covered by the projected image can be ensured to be flat, thereby ensuring the viewing quality.
The requirement of manual adjustment increases operation difficulty of the projector for a user, and the manual adjustment requires repeated adjustments to obtain a suitable size for the projected image, which increases the operation complexity of the projector.